Android : Adding action button using ADT 14

I am a new developer of Android App and learning all tips from Getting Started. I'm now on the second stage phase 2 "Adding Action Button" and stuck with adding the actions to the action bar. Here is my current situation.

1. 
   

   MyfirstApp Manifest

   
   

   
   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.example.myfirstapp"
       android:versionCode="1"
       android:versionName="1.0" >
   
       <uses-sdk
           android:minSdkVersion="11"
           android:targetSdkVersion="19" />
   
       <application
           android:allowBackup="true"
           android:icon="@drawable/ic_launcher"
           android:label="@string/app_name"
           android:theme="@style/AppTheme.Holo.Light" >
           <activity
               android:name="com.example.myfirstapp.MainActivity"
               android:label="@string/app_name" >
               <intent-filter>
                   <action android:name="android.intent.action.MAIN" />
   
                   <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
       </activity>
        <!-- A child of the main activity -->
       <activity
           android:name="com.example.myfirstapp.DisplayMessageActivity"
           android:label="@string/title_activity_display_message"
           android:parentActivityName="com.example.myfirstapp.MainActivity" >
           <!-- Parent activity meta-data to support 4.0 and lower -->
           <meta-data
               android:name="android.support.PARENT_ACTIVITY"
               android:value="com.example.myfirstapp.MainActivity" />
           </activity>
       </application>
   
   </manifest>
   
   

2.main(menu).xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
<!-- Search, should appear as action button -->
<item android:id="@+id/action_search"
      android:icon="@drawable/ic_action_search"
      android:title="@string/action_search"
      yourapp:showAsAction="ifRoom" />
<!-- Settings, should always be in the overflow -->
<item android:id="@+id/action_settings"
      android:title="@string/action_settings"
      android:showAsAction="never" />
</menu>

3.MainActivity.java

package com.example.myfirstapp;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;

@SuppressLint("ValidFragment")
public class MainActivity extends ActionBarActivity {
    public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_displaymessage);

    getActionBar().setDisplayHomeAsUpEnabled(true);
    // If your minSdkVersion is 11 or higher, instead use:
    // getActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_activity_actions, menu);
    return super.onCreateOptionsMenu(menu);
}

/** Called when the user clicks the Send button */
public void sendMessage(View view) {
    Intent intent = new Intent(this, DisplayMessageActivity.class);
    EditText editText = (EditText) findViewById(R.id.edit_message);
    String message = editText.getText().toString();
    intent.putExtra(EXTRA_MESSAGE, message);
    startActivity(intent);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle presses on the action bar items
    switch (item.getItemId()) {
        case R.id.action_search:
            openSearch();
            return true;
        case R.id.action_settings:
            openSettings();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

private void openSettings() {

}
private void openSearch() {

}

/**
 * A placeholder fragment containing a simple view.
 */
public class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        return rootView;
    }
    }
}

I see two errors from MainActivity.java

1.

inflater.inflate(R.menu.main_activity_actions, menu);

The method inflate(int, Menu) in the type MenuInflater is not applicable for the arguments (Object, Menu)

2.

case R.id.action_search:

case expressions must be constant expressions

I tried to figure out those 2 errors for couple days but I couldn't. Please help.